21703218551 has 8 divisors (see below), whose sum is σ = 24807931680. Its totient is φ = 18599568768.

The previous prime is 21703218533. The next prime is 21703218571. The reversal of 21703218551 is 15581230712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21703218551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21703218571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 221606 + ... + 304163.

It is an arithmetic number, because the mean of its divisors is an integer number (3100991460).

Almost surely, 2^21703218551 is an apocalyptic number.

21703218551 is a deficient number, since it is larger than the sum of its proper divisors (3104713129).

21703218551 is an equidigital number, since it uses as much as digits as its factorization.

21703218551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531673.

The product of its (nonzero) digits is 16800, while the sum is 35.

The spelling of 21703218551 in words is "twenty-one billion, seven hundred three million, two hundred eighteen thousand, five hundred fifty-one".